Why is Choke used in motorcycles & other vehicles?

bhargav khanparaWHY SOMETIMES WE GIVING CHOCK TO VEHICLE

Hi @#-Link-Snipped-# Khanpura Its not "chock" and it's "choke".
Chokes are widely used in bikes especially during the startup of a bike in cold condition to start the ignition. When we pull the choke, The butterfly valve in the carburetor helps in supplying rich mixture(high fuel and less air mixture) so that combustion happens with ease.When we pull the choke , the butterfly valve will be in upright position.Hope you understand.If doubt arises please ask.

So, when we use choke, just the air flow reduces? Or will there be any increase in the fuel inflow too?

lalSo, when we use choke, just the air flow reduces? Or will there be any increase in the fuel inflow too?

Yes you are correct.Its not just about the closure of air flow but also the addition of fuel into the carburetor. This happens by the process where when we pull the choke ,The butterfly valve closes the air flow which makes the pressure difference inside the carbuteror and this leads to sucking of more fuel into the carburetor .So in this process we get a air fuel mixture rich with fuel to overcome coldstarting.

A related question would be - why should choke not be used for normal functioning after engine start?

Anand TamariyaA related question would be - why should choke not be used for normal functioning after engine start?

The answer is simple.If we use choke after you get a good start , It Will lead to high fuel consumption because when we pull the choke after start, a high air fuel mixture rich in fuel Will enter into engines via inlet valve from carburetor.As a result there is a high fuel consumption .So it is better to avoid choke after a good start.

No its not only high fuel consumption, whenever you use choke when the vehicle is running, most of the vehicles stop.

Because, the choke injects high fuel and less air, this makes the engine stall as there will be no air for burning the fuel. I have tried this practically many times and it works.

Anand TamariyaA related question would be - why should choke not be used for normal functioning after engine start?

Well the choke is only used when required because the normal use of furl is easily available by the fuel tank. But the case comes when the vehicle doesn't comes up with normal fuel available. That's why choke is used to provide more than required fuel to the engine that make it to start well.
Choke is only made for emergency issues.